source3/libsmb/clireadwrite.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    client file read/write routines
   4    Copyright (C) Andrew Tridgell 1994-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21
  22 /****************************************************************************
  23   Calculate the recommended read buffer size
  24 ****************************************************************************/
  25 static size_t cli_read_max_bufsize(struct cli_state *cli)
  26 {
  27         if (!client_is_signing_on(cli) && !cli_encryption_on(cli)
  28             && (cli->posix_capabilities & CIFS_UNIX_LARGE_READ_CAP)) {
  29                 return CLI_SAMBA_MAX_POSIX_LARGE_READX_SIZE;
  30         }
  31         if (cli->capabilities & CAP_LARGE_READX) {
  32                 return cli->is_samba
  33                         ? CLI_SAMBA_MAX_LARGE_READX_SIZE
  34                         : CLI_WINDOWS_MAX_LARGE_READX_SIZE;
  35         }
  36         return (cli->max_xmit - (smb_size+32)) & ~1023;
  37 }
  38
  39 /*
  40  * Send a read&x request
  41  */
  42
  43 struct async_req *cli_read_andx_send(TALLOC_CTX *mem_ctx,
  44                                      struct event_context *ev,
  45                                      struct cli_state *cli, int fnum,
  46                                      off_t offset, size_t size)
  47 {
  48         struct async_req *result;
  49         struct cli_request *req;
  50         bool bigoffset = False;
  51
  52         uint16_t vwv[12];
  53         uint8_t wct = 10;
  54
  55         if (size > cli_read_max_bufsize(cli)) {
  56                 DEBUG(0, ("cli_read_andx_send got size=%d, can only handle "
  57                           "size=%d\n", (int)size,
  58                           (int)cli_read_max_bufsize(cli)));
  59                 return NULL;
  60         }
  61
  62         SCVAL(vwv + 0, 0, 0xFF);
  63         SCVAL(vwv + 0, 1, 0);
  64         SSVAL(vwv + 1, 0, 0);
  65         SSVAL(vwv + 2, 0, fnum);
  66         SIVAL(vwv + 3, 0, offset);
  67         SSVAL(vwv + 5, 0, size);
  68         SSVAL(vwv + 6, 0, size);
  69         SSVAL(vwv + 7, 0, (size >> 16));
  70         SSVAL(vwv + 8, 0, 0);
  71         SSVAL(vwv + 9, 0, 0);
  72
  73         if ((SMB_BIG_UINT)offset >> 32) {
  74                 bigoffset = True;
  75                 SIVAL(vwv + 10, 0,
  76                       (((SMB_BIG_UINT)offset)>>32) & 0xffffffff);
  77                 wct += 2;
  78         }
  79
  80         result = cli_request_send(mem_ctx, ev, cli, SMBreadX, 0, wct, vwv,
  81                                   0, NULL);
  82         if (result == NULL) {
  83                 return NULL;
  84         }
  85
  86         req = cli_request_get(result);
  87
  88         req->data.read.ofs = offset;
  89         req->data.read.size = size;
  90         req->data.read.received = 0;
  91         req->data.read.rcvbuf = NULL;
  92
  93         return result;
  94 }
  95
  96 /*
  97  * Pull the data out of a finished async read_and_x request. rcvbuf is
  98  * talloced from the request, so better make sure that you copy it away before
  99  * you talloc_free(req). "rcvbuf" is NOT a talloc_ctx of its own, so do not
 100  * talloc_move it!
 101  */
 102
 103 NTSTATUS cli_read_andx_recv(struct async_req *req, ssize_t *received,
 104                             uint8_t **rcvbuf)
 105 {
 106         struct cli_request *cli_req = cli_request_get(req);
 107         uint8_t wct;
 108         uint16_t *vwv;
 109         uint16_t num_bytes;
 110         uint8_t *bytes;
 111         NTSTATUS status;
 112         size_t size;
 113
 114         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 115         if (req->state == ASYNC_REQ_ERROR) {
 116                 return req->status;
 117         }
 118
 119         status = cli_pull_reply(req, &wct, &vwv, &num_bytes, &bytes);
 120
 121         if (NT_STATUS_IS_ERR(status)) {
 122                 return status;
 123         }
 124
 125         if (wct < 12) {
 126                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 127         }
 128
 129         /* size is the number of bytes the server returned.
 130          * Might be zero. */
 131         size = SVAL(vwv + 5, 0);
 132         size |= (((unsigned int)SVAL(vwv + 7, 0)) << 16);
 133
 134         if (size > cli_req->data.read.size) {
 135                 DEBUG(5,("server returned more than we wanted!\n"));
 136                 return NT_STATUS_UNEXPECTED_IO_ERROR;
 137         }
 138
 139         *rcvbuf = (uint8_t *)(smb_base(cli_req->inbuf) + SVAL(vwv + 6, 0));
 140         *received = size;
 141         return NT_STATUS_OK;
 142 }
 143
 144 /*
 145  * Parallel read support.
 146  *
 147  * cli_pull sends as many read&x requests as the server would allow via
 148  * max_mux at a time. When replies flow back in, the data is written into
 149  * the callback function "sink" in the right order.
 150  */
 151
 152 struct cli_pull_state {
 153         struct async_req *req;
 154
 155         struct event_context *ev;
 156         struct cli_state *cli;
 157         uint16_t fnum;
 158         off_t start_offset;
 159         SMB_OFF_T size;
 160
 161         NTSTATUS (*sink)(char *buf, size_t n, void *priv);
 162         void *priv;
 163
 164         size_t chunk_size;
 165
 166         /*
 167          * Outstanding requests
 168          */
 169         int num_reqs;
 170         struct async_req **reqs;
 171
 172         /*
 173          * For how many bytes did we send requests already?
 174          */
 175         SMB_OFF_T requested;
 176
 177         /*
 178          * Next request index to push into "sink". This walks around the "req"
 179          * array, taking care that the requests are pushed to "sink" in the
 180          * right order. If necessary (i.e. replies don't come in in the right
 181          * order), replies are held back in "reqs".
 182          */
 183         int top_req;
 184
 185         /*
 186          * How many bytes did we push into "sink"?
 187          */
 188
 189         SMB_OFF_T pushed;
 190 };
 191
 192 static char *cli_pull_print(TALLOC_CTX *mem_ctx, struct async_req *req)
 193 {
 194         struct cli_pull_state *state = talloc_get_type_abort(
 195                 req->private_data, struct cli_pull_state);
 196         char *result;
 197
 198         result = async_req_print(mem_ctx, req);
 199         if (result == NULL) {
 200                 return NULL;
 201         }
 202
 203         return talloc_asprintf_append_buffer(
 204                 result, "num_reqs=%d, top_req=%d",
 205                 state->num_reqs, state->top_req);
 206 }
 207
 208 static void cli_pull_read_done(struct async_req *read_req);
 209
 210 /*
 211  * Prepare an async pull request
 212  */
 213
 214 struct async_req *cli_pull_send(TALLOC_CTX *mem_ctx,
 215                                 struct event_context *ev,
 216                                 struct cli_state *cli,
 217                                 uint16_t fnum, off_t start_offset,
 218                                 SMB_OFF_T size, size_t window_size,
 219                                 NTSTATUS (*sink)(char *buf, size_t n,
 220                                                  void *priv),
 221                                 void *priv)
 222 {
 223         struct async_req *result;
 224         struct cli_pull_state *state;
 225         int i;
 226
 227         result = async_req_new(mem_ctx, ev);
 228         if (result == NULL) {
 229                 goto failed;
 230         }
 231         state = talloc(result, struct cli_pull_state);
 232         if (state == NULL) {
 233                 goto failed;
 234         }
 235         result->private_data = state;
 236         result->print = cli_pull_print;
 237         state->req = result;
 238
 239         state->cli = cli;
 240         state->ev = ev;
 241         state->fnum = fnum;
 242         state->start_offset = start_offset;
 243         state->size = size;
 244         state->sink = sink;
 245         state->priv = priv;
 246
 247         state->pushed = 0;
 248         state->top_req = 0;
 249
 250         if (size == 0) {
 251                 if (!async_post_status(result, NT_STATUS_OK)) {
 252                         goto failed;
 253                 }
 254                 return result;
 255         }
 256
 257         state->chunk_size = cli_read_max_bufsize(cli);
 258
 259         state->num_reqs = MAX(window_size/state->chunk_size, 1);
 260         state->num_reqs = MIN(state->num_reqs, cli->max_mux);
 261
 262         state->reqs = TALLOC_ZERO_ARRAY(state, struct async_req *,
 263                                         state->num_reqs);
 264         if (state->reqs == NULL) {
 265                 goto failed;
 266         }
 267
 268         state->requested = 0;
 269
 270         for (i=0; i<state->num_reqs; i++) {
 271                 SMB_OFF_T size_left;
 272                 size_t request_thistime;
 273
 274                 if (state->requested >= size) {
 275                         state->num_reqs = i;
 276                         break;
 277                 }
 278
 279                 size_left = size - state->requested;
 280                 request_thistime = MIN(size_left, state->chunk_size);
 281
 282                 state->reqs[i] = cli_read_andx_send(
 283                         state->reqs, ev, cli, fnum,
 284                         state->start_offset + state->requested,
 285                         request_thistime);
 286
 287                 if (state->reqs[i] == NULL) {
 288                         goto failed;
 289                 }
 290
 291                 state->reqs[i]->async.fn = cli_pull_read_done;
 292                 state->reqs[i]->async.priv = result;
 293
 294                 state->requested += request_thistime;
 295         }
 296         return result;
 297
 298 failed:
 299         TALLOC_FREE(result);
 300         return NULL;
 301 }
 302
 303 /*
 304  * Handle incoming read replies, push the data into sink and send out new
 305  * requests if necessary.
 306  */
 307
 308 static void cli_pull_read_done(struct async_req *read_req)
 309 {
 310         struct async_req *pull_req = talloc_get_type_abort(
 311                 read_req->async.priv, struct async_req);
 312         struct cli_pull_state *state = talloc_get_type_abort(
 313                 pull_req->private_data, struct cli_pull_state);
 314         struct cli_request *read_state = cli_request_get(read_req);
 315         NTSTATUS status;
 316
 317         status = cli_read_andx_recv(read_req, &read_state->data.read.received,
 318                                     &read_state->data.read.rcvbuf);
 319         if (!NT_STATUS_IS_OK(status)) {
 320                 async_req_error(state->req, status);
 321                 return;
 322         }
 323
 324         /*
 325          * This loop is the one to take care of out-of-order replies. All
 326          * pending requests are in state->reqs, state->reqs[top_req] is the
 327          * one that is to be pushed next. If however a request later than
 328          * top_req is replied to, then we can't push yet. If top_req is
 329          * replied to at a later point then, we need to push all the finished
 330          * requests.
 331          */
 332
 333         while (state->reqs[state->top_req] != NULL) {
 334                 struct cli_request *top_read;
 335
 336                 DEBUG(11, ("cli_pull_read_done: top_req = %d\n",
 337                            state->top_req));
 338
 339                 if (state->reqs[state->top_req]->state < ASYNC_REQ_DONE) {
 340                         DEBUG(11, ("cli_pull_read_done: top request not yet "
 341                                    "done\n"));
 342                         return;
 343                 }
 344
 345                 top_read = cli_request_get(state->reqs[state->top_req]);
 346
 347                 DEBUG(10, ("cli_pull_read_done: Pushing %d bytes, %d already "
 348                            "pushed\n", (int)top_read->data.read.received,
 349                            (int)state->pushed));
 350
 351                 status = state->sink((char *)top_read->data.read.rcvbuf,
 352                                      top_read->data.read.received,
 353                                      state->priv);
 354                 if (!NT_STATUS_IS_OK(status)) {
 355                         async_req_error(state->req, status);
 356                         return;
 357                 }
 358                 state->pushed += top_read->data.read.received;
 359
 360                 TALLOC_FREE(state->reqs[state->top_req]);
 361
 362                 if (state->requested < state->size) {
 363                         struct async_req *new_req;
 364                         SMB_OFF_T size_left;
 365                         size_t request_thistime;
 366
 367                         size_left = state->size - state->requested;
 368                         request_thistime = MIN(size_left, state->chunk_size);
 369
 370                         DEBUG(10, ("cli_pull_read_done: Requesting %d bytes "
 371                                    "at %d, position %d\n",
 372                                    (int)request_thistime,
 373                                    (int)(state->start_offset
 374                                          + state->requested),
 375                                    state->top_req));
 376
 377                         new_req = cli_read_andx_send(
 378                                 state->reqs, state->ev, state->cli,
 379                                 state->fnum,
 380                                 state->start_offset + state->requested,
 381                                 request_thistime);
 382
 383                         if (async_req_nomem(new_req, state->req)) {
 384                                 return;
 385                         }
 386
 387                         new_req->async.fn = cli_pull_read_done;
 388                         new_req->async.priv = pull_req;
 389
 390                         state->reqs[state->top_req] = new_req;
 391                         state->requested += request_thistime;
 392                 }
 393
 394                 state->top_req = (state->top_req+1) % state->num_reqs;
 395         }
 396
 397         async_req_done(pull_req);
 398 }
 399
 400 NTSTATUS cli_pull_recv(struct async_req *req, SMB_OFF_T *received)
 401 {
 402         struct cli_pull_state *state = talloc_get_type_abort(
 403                 req->private_data, struct cli_pull_state);
 404
 405         SMB_ASSERT(req->state >= ASYNC_REQ_DONE);
 406         if (req->state == ASYNC_REQ_ERROR) {
 407                 return req->status;
 408         }
 409         *received = state->pushed;
 410         return NT_STATUS_OK;
 411 }
 412
 413 NTSTATUS cli_pull(struct cli_state *cli, uint16_t fnum,
 414                   off_t start_offset, SMB_OFF_T size, size_t window_size,
 415                   NTSTATUS (*sink)(char *buf, size_t n, void *priv),
 416                   void *priv, SMB_OFF_T *received)
 417 {
 418         TALLOC_CTX *frame = talloc_stackframe();
 419         struct event_context *ev;
 420         struct async_req *req;
 421         NTSTATUS result = NT_STATUS_NO_MEMORY;
 422
 423         if (cli->fd_event != NULL) {
 424                 /*
 425                  * Can't use sync call while an async call is in flight
 426                  */
 427                 return NT_STATUS_INVALID_PARAMETER;
 428         }
 429
 430         ev = event_context_init(frame);
 431         if (ev == NULL) {
 432                 goto nomem;
 433         }
 434
 435         req = cli_pull_send(frame, ev, cli, fnum, start_offset, size,
 436                             window_size, sink, priv);
 437         if (req == NULL) {
 438                 goto nomem;
 439         }
 440
 441         while (req->state < ASYNC_REQ_DONE) {
 442                 event_loop_once(ev);
 443         }
 444
 445         result = cli_pull_recv(req, received);
 446  nomem:
 447         TALLOC_FREE(frame);
 448         return result;
 449 }
 450
 451 static NTSTATUS cli_read_sink(char *buf, size_t n, void *priv)
 452 {
 453         char **pbuf = (char **)priv;
 454         memcpy(*pbuf, buf, n);
 455         *pbuf += n;
 456         return NT_STATUS_OK;
 457 }
 458
 459 ssize_t cli_read(struct cli_state *cli, int fnum, char *buf,
 460                  off_t offset, size_t size)
 461 {
 462         NTSTATUS status;
 463         SMB_OFF_T ret;
 464
 465         status = cli_pull(cli, fnum, offset, size, size,
 466                           cli_read_sink, &buf, &ret);
 467         if (!NT_STATUS_IS_OK(status)) {
 468                 cli_set_error(cli, status);
 469                 return -1;
 470         }
 471         return ret;
 472 }
 473
 474 /****************************************************************************
 475  Issue a single SMBwrite and don't wait for a reply.
 476 ****************************************************************************/
 477
 478 static bool cli_issue_write(struct cli_state *cli,
 479                                 int fnum,
 480                                 off_t offset,
 481                                 uint16 mode,
 482                                 const char *buf,
 483                                 size_t size,
 484                                 int i)
 485 {
 486         char *p;
 487         bool large_writex = false;
 488         /* We can only do direct writes if not signing and not encrypting. */
 489         bool direct_writes = !client_is_signing_on(cli) && !cli_encryption_on(cli);
 490
 491         if (!direct_writes && size + 1 > cli->bufsize) {
 492                 cli->outbuf = (char *)SMB_REALLOC(cli->outbuf, size + 1024);
 493                 if (!cli->outbuf) {
 494                         return False;
 495                 }
 496                 cli->inbuf = (char *)SMB_REALLOC(cli->inbuf, size + 1024);
 497                 if (cli->inbuf == NULL) {
 498                         SAFE_FREE(cli->outbuf);
 499                         return False;
 500                 }
 501                 cli->bufsize = size + 1024;
 502         }
 503
 504         memset(cli->outbuf,'\0',smb_size);
 505         memset(cli->inbuf,'\0',smb_size);
 506
 507         if (cli->capabilities & CAP_LARGE_FILES) {
 508                 large_writex = True;
 509         }
 510
 511         if (large_writex) {
 512                 cli_set_message(cli->outbuf,14,0,True);
 513         } else {
 514                 cli_set_message(cli->outbuf,12,0,True);
 515         }
 516
 517         SCVAL(cli->outbuf,smb_com,SMBwriteX);
 518         SSVAL(cli->outbuf,smb_tid,cli->cnum);
 519         cli_setup_packet(cli);
 520
 521         SCVAL(cli->outbuf,smb_vwv0,0xFF);
 522         SSVAL(cli->outbuf,smb_vwv2,fnum);
 523
 524         SIVAL(cli->outbuf,smb_vwv3,offset);
 525         SIVAL(cli->outbuf,smb_vwv5,0);
 526         SSVAL(cli->outbuf,smb_vwv7,mode);
 527
 528         SSVAL(cli->outbuf,smb_vwv8,(mode & 0x0008) ? size : 0);
 529         /*
 530          * According to CIFS-TR-1p00, this following field should only
 531          * be set if CAP_LARGE_WRITEX is set. We should check this
 532          * locally. However, this check might already have been
 533          * done by our callers.
 534          */
 535         SSVAL(cli->outbuf,smb_vwv9,(size>>16));
 536         SSVAL(cli->outbuf,smb_vwv10,size);
 537         /* +1 is pad byte. */
 538         SSVAL(cli->outbuf,smb_vwv11,
 539               smb_buf(cli->outbuf) - smb_base(cli->outbuf) + 1);
 540
 541         if (large_writex) {
 542                 SIVAL(cli->outbuf,smb_vwv12,(((SMB_BIG_UINT)offset)>>32) & 0xffffffff);
 543         }
 544
 545         p = smb_base(cli->outbuf) + SVAL(cli->outbuf,smb_vwv11) -1;
 546         *p++ = '\0'; /* pad byte. */
 547         if (!direct_writes) {
 548                 memcpy(p, buf, size);
 549         }
 550         if (size > 0x1FFFF) {
 551                 /* This is a POSIX 14 word large write. */
 552                 set_message_bcc(cli->outbuf, 0); /* Set bcc to zero. */
 553                 _smb_setlen_large(cli->outbuf,smb_size + 28 + 1 /* pad */ + size - 4);
 554         } else {
 555                 cli_setup_bcc(cli, p+size);
 556         }
 557
 558         SSVAL(cli->outbuf,smb_mid,cli->mid + i);
 559
 560         show_msg(cli->outbuf);
 561         if (direct_writes) {
 562                 /* For direct writes we now need to write the data
 563                  * directly out of buf. */
 564                 return cli_send_smb_direct_writeX(cli, buf, size);
 565         } else {
 566                 return cli_send_smb(cli);
 567         }
 568 }
 569
 570 /****************************************************************************
 571   write to a file
 572   write_mode: 0x0001 disallow write cacheing
 573               0x0002 return bytes remaining
 574               0x0004 use raw named pipe protocol
 575               0x0008 start of message mode named pipe protocol
 576 ****************************************************************************/
 577
 578 ssize_t cli_write(struct cli_state *cli,
 579                  int fnum, uint16 write_mode,
 580                  const char *buf, off_t offset, size_t size)
 581 {
 582         ssize_t bwritten = 0;
 583         unsigned int issued = 0;
 584         unsigned int received = 0;
 585         int mpx = 1;
 586         size_t writesize;
 587         int blocks;
 588
 589         if(cli->max_mux > 1) {
 590                 mpx = cli->max_mux-1;
 591         } else {
 592                 mpx = 1;
 593         }
 594
 595         /* Default (small) writesize. */
 596         writesize = (cli->max_xmit - (smb_size+32)) & ~1023;
 597
 598         if (write_mode == 0 &&
 599                         !client_is_signing_on(cli) &&
 600                         !cli_encryption_on(cli) &&
 601                         (cli->posix_capabilities & CIFS_UNIX_LARGE_WRITE_CAP) &&
 602                         (cli->capabilities & CAP_LARGE_FILES)) {
 603                 /* Only do massive writes if we can do them direct
 604                  * with no signing or encrypting - not on a pipe. */
 605                 writesize = CLI_SAMBA_MAX_POSIX_LARGE_WRITEX_SIZE;
 606         } else if ((cli->capabilities & CAP_LARGE_WRITEX) &&
 607                         (strcmp(cli->dev, "LPT1:") != 0)) {
 608
 609                 /* Printer devices are restricted to max_xmit
 610                  * writesize in Vista and XPSP3. */
 611
 612                 if (cli->is_samba) {
 613                         writesize = CLI_SAMBA_MAX_LARGE_WRITEX_SIZE;
 614                 } else if (!client_is_signing_on(cli)) {
 615                         /* Windows restricts signed writes to max_xmit.
 616                          * Found by Volker. */
 617                         writesize = CLI_WINDOWS_MAX_LARGE_WRITEX_SIZE;
 618                 }
 619         }
 620
 621         blocks = (size + (writesize-1)) / writesize;
 622
 623         while (received < blocks) {
 624
 625                 while ((issued - received < mpx) && (issued < blocks)) {
 626                         ssize_t bsent = issued * writesize;
 627                         ssize_t size1 = MIN(writesize, size - bsent);
 628
 629                         if (!cli_issue_write(cli, fnum, offset + bsent,
 630                                         write_mode,
 631                                         buf + bsent,
 632                                         size1, issued))
 633                                 return -1;
 634                         issued++;
 635                 }
 636
 637                 if (!cli_receive_smb(cli)) {
 638                         return bwritten;
 639                 }
 640
 641                 received++;
 642
 643                 if (cli_is_error(cli))
 644                         break;
 645
 646                 bwritten += SVAL(cli->inbuf, smb_vwv2);
 647                 if (writesize > 0xFFFF) {
 648                         bwritten += (((int)(SVAL(cli->inbuf, smb_vwv4)))<<16);
 649                 }
 650         }
 651
 652         while (received < issued && cli_receive_smb(cli)) {
 653                 received++;
 654         }
 655
 656         return bwritten;
 657 }
 658
 659 /****************************************************************************
 660   write to a file using a SMBwrite and not bypassing 0 byte writes
 661 ****************************************************************************/
 662
 663 ssize_t cli_smbwrite(struct cli_state *cli,
 664                      int fnum, char *buf, off_t offset, size_t size1)
 665 {
 666         char *p;
 667         ssize_t total = 0;
 668
 669         do {
 670                 size_t size = MIN(size1, cli->max_xmit - 48);
 671
 672                 memset(cli->outbuf,'\0',smb_size);
 673                 memset(cli->inbuf,'\0',smb_size);
 674
 675                 cli_set_message(cli->outbuf,5, 0,True);
 676
 677                 SCVAL(cli->outbuf,smb_com,SMBwrite);
 678                 SSVAL(cli->outbuf,smb_tid,cli->cnum);
 679                 cli_setup_packet(cli);
 680
 681                 SSVAL(cli->outbuf,smb_vwv0,fnum);
 682                 SSVAL(cli->outbuf,smb_vwv1,size);
 683                 SIVAL(cli->outbuf,smb_vwv2,offset);
 684                 SSVAL(cli->outbuf,smb_vwv4,0);
 685
 686                 p = smb_buf(cli->outbuf);
 687                 *p++ = 1;
 688                 SSVAL(p, 0, size); p += 2;
 689                 memcpy(p, buf + total, size); p += size;
 690
 691                 cli_setup_bcc(cli, p);
 692
 693                 if (!cli_send_smb(cli))
 694                         return -1;
 695
 696                 if (!cli_receive_smb(cli))
 697                         return -1;
 698
 699                 if (cli_is_error(cli))
 700                         return -1;
 701
 702                 size = SVAL(cli->inbuf,smb_vwv0);
 703                 if (size == 0)
 704                         break;
 705
 706                 size1 -= size;
 707                 total += size;
 708                 offset += size;
 709
 710         } while (size1);
 711
 712         return total;
 713 }